API 17D Gate Valves

[metboss]

Hi,

We have placed the order for Sub-sea API 17D Gate Valves with API Monogram requirement. We are informed by the supplier that Gate Valve will be supplied as per API 6A design with Hydraulic Actuator (as per API 17D). However, this Gate Valve Assembly will not be monogrammed due to mix-up of two different specs (API 6A & API 17D). As per my understanding, at least Gate Valve can be individually monogrammed to API 6A. But, supplier says it is not possible due to Valve assembly with Actuator having 2 different specs.

My questions a)Why can’t individual item monogrammed to their respective spec?
b) Can we use API 6A Gate Valve for Sub-sea application? What is the significant difference between API 6A and API 17D Gate valves in reference to Design, Performance requirement (PR2) & testing’s?

Appreciate your feedback. Thank you.

 

[jmec87]

a)Why can’t individual item monogrammed to their respective spec?

The valve prepared for actuator, if assembled with the actuator, shall meet all the requirements of actuated valves.

If the supplier provided you the valve and actuator separately (not assembled together), they could probably monogram both of them (provided they have the appropriate monogram licenses). Because they are supplying the valve with the actuator installed, the actuated valve (including the actuator) would be required to conform to API 6A for it to be monogrammable.

Can we use API 6A Gate Valve for Sub-sea application?

Verify with the manufacturer that it is suitable for sub-sea. Also check if you have any applicable legal or regulatory requirements for the gate valve to conform to API 17D or another spec (this is jurisdiction-dependent).

What is the significant difference between API 6A and API 17D Gate valves in reference to Design, Performance requirement (PR2) & testing’s?

The API 17D design requirements are based on 6A, including a requirement in 17D 5.1.3.4 that "Pressure-containing component designs shall conform to API 6A." 17D has some additional and modified requirements. The 17D hydro-test requirements are also essentially the same: per 17D 5.4.5.1 "Procedures for hydrostatic pressure testing of equipment specified in Section 6 through Section 11 shall conform to the quirements for PSL 2, PSL 3, or PSL 3G in accordance with API 6A, with the exception that parts may be painted prior to testing." API 17D appears to require more cycles for valve validation. Note also that if you want API 6A validation per Annex F, then you need to specify PR2F and not just PR2.

 

[gerhardl]

If you are supplying to an end user, you could look at this on a general basis.

The questions that need to be clarified would be:
What can the end user actually accept? (products,tests,approvals)
What solutions/products were used/accepted before, if any.
Competition from other products/suppliers?

On a general basis two products with different, or even the same tests/approval, will not meet the requirements of the given approval if mounted and working together as a unit. An actuator and valve supplied separately would be a typical example of this. The reason is that the actuator would have to be mounted correctly, tested, stroke controlled (end and limit switches adjusted, solenoid valves and/or steering and control checked etc.)

As jemc87 says, your supplier could (if licensed) do this for an assembly.

Qustion:
End user clarification of tests/products involved (actuator,valve,limit switches,torque switches, solenoid valves, other)
Is it possible to te have tests/certifications done by a third party?
Just approval (under license) or practical tests?

I suspect your questions to be what typical occurs when a new supplier replace old, established routines. You have to recheck what is acceptable and necessary.

Good luck!

 

[metboss]

Thank you jmec87 and gerhard for your feedback. It is now accepted by end user. After assembly, FAT will be done with third party witness. Moreover, it is not going to be permanently installed for Sub-sea application. After intended operation, it will be retrieved.